At the start of the Cold War, the greatest threat
to America wasn't the Russians and the looming
Communist threat. Rather, it was an elite
organization bent on world domination, a group so
powerful only nuclear weapons could safeguard
against them. The CIA knew what these men were
capable of, and in a last ditch attempt to protect
America against them, they built two high-security
arsenals deep within the earth--one declassified
in the Nevada desert, and one heavily under wraps
in Antarctica. For over 50 years, no one spoke of
The Citadel, the fortress deep under the ice in
Antarctica that held the most powerful weapon
known to man--until the Organization returned,
hellbent on destruction.

Captain Jim Vaughn is a government agent known for
performing missions no one else wants. So when an
old colleague approaches him with an assignment,
he can't refuse--even if the mission has been set
in motion by a dead man's letter, found in
Antarctica and dated 1949. The Citadel has been
cracked, and the only man who can safeguard it is
Vaughn. Nothing short of the fate of mankind rests
on his shoulders.